The present invention relates generally to a probe system for testing a semiconductor wafer or the like by using a probe card, particularly relates to an improvement thereof in connection with an exchange of the probe card.
A conventional probe system 2 shown in FIGS. 6A and 6B is integrated with a loader system 1 which transfers a semiconductor wafer W, and is designed to test electric characteristics of the wafer W delivered from the loader system 1. In the loader system 1, a cassette housing section 3, a wafer transfer mechanism 4 and a sub-chuck 5 are provided. The sub-chuck 5 is designed to pre-align the wafer W on the basis of an orientation flat or notch of the wafer W when the wafer W is transferred by the wafer transfer mechanism 4.
In the probe system 2, a supporting table (main chuck) 6, an alignment mechanism 7 and a probe card 8 are provided for the test. The main chuck 6 can support thereon the wafer W delivered from the transfer mechanism 4 of the loader system 1, and is movable in horizontal and vertical directions and rotatable about a vertical axis. The alignment mechanism 7 is designed to precisely align the wafer W on the main chuck 6. The probe card 8 has probe needles 8A for testing the aligned wafer W by electrically contacting electrode pads of the wafer W. The probe card 8 is fixed to a head plate 9, which forms a ceiling surface of the probe system 2, by means of a card clamp mechanism (not shown)
On the head plate 9 of the probe system 2, a test head T is provided. The test head T is electrically and detachably connected to the probe card 8 via a pogo ring (not shown). Signals from a tester (not shown) are transmitted to the electrode pads on the wafer W to test electric characteristics of a plurality of semiconductor elements (chips) formed on the wafer W.
By the way, when such a test is carried out, it is required to exchange the probe card 8 in accordance with the kind of the wafer W. When a new probe card 8 is mounted, a manually-operatable card exchanging system (not shown) is introduced from the outside of the probe system 2, and a probe card 8 with a card holder is mounted on the main chuck 6 by means of the card exchanging system. Then, the main chuck 6 is horizontally moved to the central portion in the probe system 2 and lifted to the card clamp mechanism (not shown). Then, the card clamp mechanism operates to clamp the card holder of the probe card 8, so that the probe card 8 is fixed to the head plate 9. Then, the card exchanging system is returned to the original position outside of the probe system 2.
Thus, in the conventional probe system, the probe card 8 is transferred to the main chuck 6 by means of the card exchanging system, and is upwardly moved to the card claim mechanism by means of the main chuck 6 to be mounted. Therefore, the card claim mechanism must be provided in the probe system 2 in addition to the card exchanging system. If the main chuck 6 can not be precisely aligned with the clamp mechanism when the probe card 8 is exchanged, there are some cases where the probe card 8 can not be properly delivered between the main chuck 6 and the clamp mechanism. If the probe card 8 can not be properly delivered, there are same cases where the main chuck 6 may be damaged.
It is therefore an object of the present invention to provide a probe system capable of shortening the time required to exchange a probe card without the need of an independent card clamp mechanism, and capable of preventing a supporting table from being damaged.
In order to accomplish this object, the present invention provides a probe system comprising: a case defining a prober chamber for receiving an object to be tested, the case having an opening capable of being open and closed on one side thereof; a head plate forming a ceiling portion of the case; a test head provided on the head plate; a probe card detachably connected to the test head; a card supporting member supporting the probe card; a vertically moving mechanism for moving the card supporting member in vertical directions with respect to the head plate such that the probe card is connected/disconnected to/from the test head; and a horizontally moving mechanism for moving the card supporting member in substantially horizontal directions between a connecting position at which the probe card is connected and a region near the opening of the case.
This probe system preferably further comprises: a positioning mechanism for positioning the card supporting member in horizontal directions with respect to the head plate; and a backlash preventing mechanism for preventing backlash of the card supporting member positioned by the positioning mechanism with respect to the head plate.
In this probe system, the horizontally moving mechanism may comprise: a pair of first retractable mechanisms retractable while supporting the card supporting member from both sides; a pair of second retractable mechanisms retractable while supporting the first retractable mechanisms with respect to the head plate, respectively; and a pair of driving mechanisms for driving the second retractable mechanisms to extend and retract the second retractable mechanisms.
In that case, the probe system preferably further comprises a stopper mechanism for restricting extension and retraction of the first retractable mechanisms.
In this probe system, the vertically moving mechanism preferably comprises: a main lift mechanism for downwardly moving the card supporting member with respect to the head plate so as to remove the probe card from the test head, and for upwardly moving the card supporting member with respect to the head plate so as to temporarily connect the probe cared to the test head; and an auxiliary lift mechanism for further upwardly moving the card supporting member with respect to the head plate so as to completely connect the temporarily connected probe card to the test head.
In that case, the auxiliary lift mechanism may be a cam mechanism.